Apparatus and method of reproducing surround wave field using wave field synthesis based on speaker array

ABSTRACT

Disclosed are an apparatus and method of surround wave field synthesizing a multi-channel signal excluding sound image localization information. A wave field synthesis and reproduction apparatus may include a signal classification unit to classify an inputted multi-channel signal into a primary signal and an ambient signal, a sound image localization information estimation unit to estimate sound image localization information of the primary signal and sound image localization information of the ambient signal, and a rendering unit to render the primary signal and the ambient signal based on the sound image localization information of the primary signal, the sound image localization information of the ambient signal, and listener environment information.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Korean PatentApplication No. 10-2010-0111529, filed on Nov. 10, 2010, in the KoreanIntellectual Property Office, the disclosure of which is incorporatedherein by reference.

BACKGROUND

1. Field

Example embodiments relate to an apparatus and method of synthesizingand reproducing a surround wave field, and more particularly, relate toan apparatus and method of surround wave field synthesizing amulti-channel signal excluding sound image localization information.

2. Description of the Related Art

A wave field synthesis and reproduction scheme may correspond to atechnology capable of providing the same sound field to severallisteners in a listening space by plane-wave reproducing a sound sourceto be reproduced.

However, to process a sound field signal by the wave field synthesis andreproduction scheme, a sound source signal and sound image localizationinformation about the way of localizing the source signal in thelistening space may be used. Thus, the wave field synthesis andreproduction scheme may be difficult to be applied to a mixed discretemulti-channel signal excluding the sound image localization information.

A scheme of performing a wave field synthesis rendering by consideringeach channel of a multi-channel signal, such as a 5.1 channel, as asound source, and by considering the sound image localizationinformation using information about an angle of a speaker configurationhas been developed. However, the scheme has a problem of causing anunintended wave field distortion phenomenon, and may not achieve anunrestricted sound image localization that is a merit of a wave fieldsynthesis scheme.

Accordingly, a scheme capable of performing the wave field synthesisrendering in the discrete multi-channel signal without the wave fielddistortion phenomenon is desired.

SUMMARY

The present invention may provide an apparatus and method of minimizinga distortion with respect to sound field information by classifying amulti-channel signal into a primary signal and an ambient signal andreproducing the classified signals.

The foregoing and/or other aspects are achieved by providing a wavefield synthesis and reproduction apparatus including a signalclassification unit to classify an inputted multi-channel signal into aprimary signal and an ambient signal, a sound image localizationinformation estimation unit to estimate sound image localizationinformation indicating a localization of the primary signal and soundimage localization information indicating a localization of the ambientsignal, and a rendering unit to render the primary signal and theambient signal based on the sound image localization information of theprimary signal, the sound image localization information of the ambientsignal, and listener environment information.

When the direction information and the sound image localizationinformation of the primary signal indicate the same direction, therendering unit may render the primary signal using a wave fieldsynthesis scheme. When the direction information and the sound imagelocalization information of the primary signal indicate differentdirections, the rendering unit may render the primary signal using abeamforming scheme.

When the direction information and the sound image localizationinformation of the ambient signal indicate the same direction, therendering unit may render the ambient signal using a wave fieldsynthesis scheme. When the direction information and the sound imagelocalization information of the ambient signal indicate differentdirections, the rendering unit may render the ambient signal using abeamforming scheme.

The foregoing and/or other aspects are achieved by providing a wavefield synthesis and reproduction method including classifying aninputted multi-channel signal into a primary signal and an ambientsignal, estimating sound image localization information indicating alocalization of the primary signal and sound image localizationinformation indicating a localization of the ambient signal, andrendering the primary signal and the ambient signal based on the soundimage localization information of the primary signal, the sound imagelocalization information of the ambient signal, and listener environmentinformation.

According to an embodiment, a distortion with respect to sound fieldinformation may be minimized by classifying a multi-channel signal intoa primary signal and an ambient signal and reproducing the classifiedsignals.

According to an embodiment, a separate interaction with respect to acorresponding signal may be added by classifying a multi-channel signalinto a primary signal and an ambient signal.

Additional aspects of embodiments will be set forth in part in thedescription which follows and, in part, will be apparent from thedescription, or may be learned by practice of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects will become apparent and more readilyappreciated from the following description of embodiments, taken inconjunction with the accompanying drawings of which:

FIG. 1 is a block diagram illustrating a wave field synthesis andreproduction apparatus according to example embodiments;

FIG. 2 is a block diagram illustrating an apparatus for generating amulti-channel signal inputted to a wave field synthesis and reproductionapparatus according to example embodiments; and

FIG. 3 is a flowchart illustrating a method of synthesizing andreproducing a wave field according to example embodiments.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of whichare illustrated in the accompanying drawings, wherein like referencenumerals refer to the like elements throughout. Embodiments aredescribed below to explain the present disclosure by referring to thefigures. A method of synthesizing and reproducing a wave field may beimplemented by a wave field synthesis and reproduction apparatus.

FIG. 1 is a block diagram illustrating a wave field synthesis andreproduction apparatus according to example embodiments.

Referring to FIG. 1, the wave field synthesis and reproduction apparatusaccording to example embodiments may include a signal classificationunit 110, a sound image localization information estimation unit 120,and a rendering unit 130.

The signal classification unit 110 may classify an inputtedmulti-channel signal into a primary signal and an ambient signal. Inthis instance, the multi-channel signal may correspond to a discretemulti-channel signal such as a 5.1 channel signal. The signalclassification unit 110 may correspond to an upmixer having aconfiguration of separating the primary signal from the ambient signal.The signal classification unit 110 may separate the primary signal fromthe ambient signal using one of various algorithms that separate theprimary signal from the ambient signal.

An algorithm used for classifying the primary signal and the ambientsignal by the signal classification unit 110 may be different from asound-source separation algorithm which extracts the entire sound sourceincluded in an audio signal in that the algorithm separates only aportion of a sound source object from the entire sound source includedin the audio signal.

The sound image localization information estimation unit 120 mayestimate sound image localization information indicating a localizationof the primary signal and the ambient signal classified by the signalclassification unit 110.

Referring to FIG. 1, the sound image localization information estimationunit 120 may include a primary signal sound image localizationinformation estimation unit 121 and an ambient signal sound imagelocalization information estimation unit 122. The primary signal soundimage localization information estimation unit 121 may estimate thesound image localization information of the primary signal based onlocalization information of the multi-channel signal and the primarysignal. The ambient signal sound image localization informationestimation unit 122 may estimate the sound image localizationinformation of the ambient signal based on localization information ofthe multi-channel signal and the ambient signal. The localizationinformation of the multi-channel signal may include information about adistribution between each channel of the multi-channel signal.

The rendering unit 130 may render the primary signal and the ambientsignal based on the sound image localization information of the primarysignal, the sound image localization information of the ambient signal,and listener environment information. The listener environmentinformation may correspond to number information indicating a number ofspeakers reproducing the multi-channel signal, interval informationindicating an interval between speakers, and direction informationindicating a direction of each speaker. The direction information ofeach speaker may correspond to information indicating a direction of adisposed speaker array, such as the front, the side, and the rear.

Referring to FIG. 1, the rendering unit 130 may include a wave fieldsynthesis (WFS) rendering unit 131 and a beamforming unit 132. Here, theWFS rendering unit 131 may render the primary signal or the ambientsignal using a WFS. The beamforming unit 132 may render the ambientsignal using a beamforming scheme.

In particular, when the direction information of the speaker included inthe listener environment information and the sound image localizationinformation of the primary signal and the sound image localizationinformation of the ambient signal indicate the same direction, therendering unit 130 may command the WFS rendering unit 131 to render theprimary signal and the ambient signal using the WFS.

Also, when the direction information of the speaker included in thelistener environment information and the sound image localizationinformation of the primary signal, or the sound image localizationinformation of the ambient signal indicate different directions, therendering unit 130 may render the primary signal or the ambient signalindicating a different direction using the beamforming.

FIG. 2 is a block diagram illustrating an apparatus for generating amulti-channel signal inputted to a wave field synthesis and reproductionapparatus according to example embodiments.

Referring to FIG. 2, the multi-channel signal inputted to the wave fieldsynthesis and reproduction apparatus according to an embodiment maycorrespond to a signal generated by synthesizing a plurality of soundsource objects by using a channel mixer configured by a panning scheme.

FIG. 3 is a flowchart illustrating a method of synthesizing andreproducing a wave field according to example embodiments.

In operation S310, the signal classification unit 110 may classify aninputted multi-channel signal into a primary signal and an ambientsignal.

In operation S320, the sound image localization information estimationunit 120 may estimate sound image localization information indicating alocalization of the primary signal and the ambient signal classified inoperation S310. In particular, the primary signal sound imagelocalization information estimation unit 121 may estimate the soundimage localization information of the primary signal and the sound imagelocalization information of the ambient signal based on localizationinformation of the multi-channel signal, the primary signal, and theambient signal.

In operation S330, the rendering unit 130 may receive an input oflistener environment information, and the sound image localizationinformation of the primary signal and the sound image localizationinformation of the ambient signal estimated in operation S320, and mayverify whether direction information indicating a direction of a speakerincluded in the listener environment information, the sound imagelocalization information of the primary signal, and the sound imagelocalization information of the ambient signal indicate the samedirection.

When the direction information of the speaker and one of the sound imagelocalization information of the primary signal and the sound imagelocalization information of the ambient signal are determined toindicate the same direction in operation S330, the rendering unit 130may render the primary signal or the ambient signal determined toindicate the same direction as the direction information of the speakerincluded in the listener environment information using a WFS inoperation S340.

Also, when the direction information of the speaker and one of the soundimage localization information of the primary signal and the sound imagelocalization information of the ambient signal are determined toindicate different directions in operation S330, the rendering unit 130may render the primary signal or the ambient signal determined toindicate a different direction using the beamforming in operation S350.

According to an embodiment, a distortion with respect to sound fieldinformation may be minimized by classifying a multi-channel signal intoa primary signal and an ambient signal and reproducing the classifiedsignals. According to an embodiment, a separate interaction with respectto a corresponding signal may be added by classifying a multi-channelsignal into a primary signal and an ambient signal.

Although embodiments have been shown and described, it would beappreciated by those skilled in the art that changes may be made inthese embodiments without departing from the principles and spirit ofthe disclosure, the scope of which is defined by the claims and theirequivalents.

What is claimed is:
 1. An apparatus comprising: a signal classificationunit to classify an inputted multi-channel signal into a primary signaland an ambient signal; a sound image localization information estimationunit to estimate sound image localization information correspondinglyindicating a localization of the primary signal and a localization ofthe ambient signal; and a rendering unit to render the primary signaland the ambient signal based on a result of direction verification ofthe sound image localization information corresponding with the primarysignal and the ambient signal, relative to a direction indicated inlistener environment information.
 2. The apparatus of claim 1, whereinthe listener environment information comprises number informationindicating a number of speakers reproducing the multi-channel signal,interval information indicating an interval between the speakers, anddirection information indicating a direction of each speaker.
 3. Theapparatus of claim 2, wherein, when the direction information and thesound image localization information of the primary signal indicate thesame direction, the rendering unit renders the primary signal using awave field synthesis (WFS) scheme.
 4. The apparatus of claim 3, wherein,when the direction information and the sound image localizationinformation of the primary signal indicate different directions, therendering unit renders the primary signal using a beamforming scheme. 5.The apparatus of claim 2, wherein, when the direction information andthe sound image localization information of the ambient signal indicatethe same direction, the rendering unit renders the ambient signal usinga WFS scheme.
 6. The apparatus of claim 5, wherein, when the directioninformation and the sound image localization information of the ambientsignal indicate different directions, the rendering unit renders theambient signal using a beamforming scheme.
 7. The apparatus of claim 1,wherein the sound image localization information estimation unitcomprises: a primary signal sound image localization informationestimation unit to estimate the sound image localization information ofthe primary signal based on localization information of themulti-channel signal and the primary signal; and an ambient signal soundimage localization information estimation unit to estimate the soundimage localization information of the ambient signal based onlocalization information of the multi-channel signal and the ambientsignal.
 8. The apparatus of claim 1, wherein, by using a channel mixerconfigured by a panning scheme, the multi-channel signal is generated bysynthesizing a plurality of sound source objects.
 9. The apparatus ofclaim 1, wherein the signal classification unit corresponds to anupmixer having a predetermined configuration.
 10. A method comprising:classifying an inputted multi-channel signal into a primary signal andan ambient signal; estimating sound image localization informationcorrespondingly indicating a localization of the primary signal and alocalization of the ambient signal; and rendering the primary signal andthe ambient signal based on a result of direction verification of thesound image localization information corresponding with the primarysignal and the ambient signal, relative to a direction indicated inlistener environment information.
 11. The method of claim 10, whereinthe listener environment information includes number informationindicating a number of speakers reproducing the multi-channel signal,interval information indicating an interval between speakers, anddirection information indicating a direction of each speaker.
 12. Themethod of claim 11, wherein, when the direction information and thesound image localization information of the primary signal indicate thesame direction, the rendering comprises rendering the primary signalusing a wave field synthesis (WFS) scheme.
 13. The method of claim 12,wherein, when the direction information and the sound image localizationinformation of the primary signal indicate different directions, therendering comprises rendering the primary signal using a beamformingscheme.
 14. The method of claim 11, wherein, when the directioninformation and the sound image localization information of the ambientsignal indicate the same direction, the rendering comprises renderingthe ambient signal using a WFS scheme.
 15. The method of claim 14,wherein, when the direction information and the sound image localizationinformation of the ambient signal indicate different directions, therendering comprises rendering the ambient signal using a beamformingscheme.
 16. The method of claim 10, wherein the estimating comprises:estimating the sound image localization information of the primarysignal based on localization information of the multi-channel signal andthe primary signal; and estimating the sound image localizationinformation of the ambient signal based on localization information ofthe multi-channel signal and the ambient signal.
 17. The method of claim10, wherein, by using a channel mixer configured by a panning scheme,the multi-channel signal is generated by synthesizing a plurality ofsound source objects.